Spinning funnel



J1me 1950 H. P. VERSCHRAGEN 2,9

SPINNING FUNNEL Filed Aug. 3, 1959 HERMANUS PETRUS VERSCHRAGEN 1N VEN TOR.

AT NE United States Patent SPINNING FUNNEL Hermanus Petrus Verschragen, Arnhem, Netherlands, as-

signor to American Erika Corporation, Enka, N.C., a corporation of Delaware Filed Aug. 3, 1959, Ser. No. 831,093

Claims priority, application Netherlands Sept. 2, 1958 6 Claims. (Cl. 57-76) This invention relates to the manufacture of rayon by the centrifugal process and more particularly to an improved spinning funnel for use in the aforesaid process. In the manufacture of rayon by the centrifugal process, the thread after being spun and extruded through a coagulating medium is collected in a centrifuge, bucket or pot which is rotated at a relatively high speed. The thread is laid up in the form of a cake by means of the centrifugal force created by the rotation of the bucket and the movement of the thread guide funnel.

In US. Patent No. 2,100,595, of common ownership herewith, it was proposed to provide the thread guiding outlet of these funnels with a corrugated or undulated surface, that is, to provide the outlet with a series of projections and depressions. This corrugated surface is used to prevent the formation of too compact or hard layers which would hinder satisfactory processing of the cakes. This solved the problem of cake permeability, but other problems were still unsolved.

The thread contacts and rides around the mouth of the funnel as it emerges from the outlet at the lower end thereof and thereby creates considerable friction. This is detrimental to the freshly spun, extremely sensitive, gelatinous thread. In addition, such friction will after a period of time cause a wearing away of the wall of the spinning funnel adjacent its mouth and thereby reduce the effective life of the spinning funnel. it was proposed in US. Patent No. 2,177,322, also of common owner ship herewith, that this problem could be overcome by etching the thread guiding surface adjacent its outlet end by the use of an etching liquid or a sand blast. This provides a myriad of depressed portions which are capable of entrapping liquid and which thereby form an antifriction surface for the thread.

The reduction of friction makes it possible to produce thicker yarn packages because the centrifugal force uti lized in the package formation is reduced by the frictional force at the thread discharge end of the funnel. Thus, as the package grows and the centrifugal force decreases, it will soon approximate that of the frictional force. Therefore, any decrease in this frictional force will lengthen the cycle before the two forces approach each other.

When using the funnels of the aforesaid patents, certain problems have been found to exist. It is very difficult, if not impossible, to obtain a very even surface on the funnel by etching with a liquid such as hydrofluoric acid or by sand blasting. Thus the frictional force at various points on the funnel is unequal, thereby causing irregularities in the thread. In addition, such surface has a very short life and must renewed again and again. This weakens the funnels and causes them to break off in the pots or requires frequent replacement.

It is therefore an object of this invention to provide a spinning funnel that is free of the difiiculties of those of the prior art.

Another object of this invention is to provide a spinning funnel the discharge end of which is constructed in such a fashion that the frictional force exerted against the thread passing thereover is substantially even.

A further object of this invention is to provide spinning funnels the discharge ends of which may be constructed simply and identically.

These and other objects may be accomplished by providing the discharge end of the spinning funnel with a series of projections and depressions which have at least two concentric annular rims separated by an annular groove. These rims extend in the peripheral direction of the funnel and projection in the axial direction a substantially equal distance. Such rims permit the accumulation of liquid in the annular groove separating them during the centrifugal process for manufacturing rayon. This accumulation of liquid substantially reduces the friction generated by the thread passing over the funnel discharge end.

Other objects and advantages will be apparent from the following detailed description taken in conjunction with the accompanying drawings wherein Figure 1 is an elevational view, partly in section, of the improved funnel of this invention, and

Figure 2 is a perspective view of the lower portion of this improved funnel.

Referring now to the drawings, reference numeral 1 indicates generally a spinning funnel utilized in the man ufacture of rayor by the centrifugal process. The spinning machine, centrifuge or pot and reciprocating aim for the funnel have been omitted from the drawing for the sake of clarity, it being understood that such are of conventional design and well known to those skilled inthe art. Funnel 1 is provided with a plurality of narrow or necked down portions 2 along which thread 3 slides during the collection operation, a conical mouth 7 through which thread 3 enters the funnel, and a discharge end 4 through which the thread passes from the funnel to the centrifuge (not shown).

The discharge end 4 of funnel 1 is provided with a series of projections 5 with the resultant depressions 10 therebetween. The thread traveling over this series of projections and depressions is caused to undulate. This movement is aided by the conventional traversing movement of the funnel along the axis of the rotating centrifuge. As pointed out in US. Patent No. 2,100,595, this combined movement causes the thread being collected to move in a sinuous or undulating manner. This deposition of the thread prevents a number of separate convolutions from superimposing upon each other.

Two rims 8 and 9 extending in the peripheral direction of the funnel and projecting in the axial direction a substantially equal distance are provided on the series of projections 5 and the depressions 10 formed therebetween. Rims 8 and 9 should project between 0.15 and 0.25 mm. and preferably about 0.2 mm. These rims are in spaced relationship to each other and form therebetween a groove 6 of a depth between 0.15 and 0.25 mm. depending upon the projection distance of rims S and 9. Groove 6 should not be too wide since this might weaken the funnel. It is preferably about 1.0 mm. in width. In normal situations only one groove will be provided, however, for thicker funnels more than one may be used to provide a larger antifriction surface.

In applying the improved spinning funnel of the present invention, it can readily be seen that liquid carried along with freshly spun thread 3 will be stripped from the thread by rim 8 and be collected in groove 6, thereby providing an antifriction thread travel surface.

This funnel generally is constructed of glass or its equivalent. It may be fashioned so as to conform to this invention by the use of a mold. The discharge end 4 should be heated and pressed into a mold whose molddischarge end 4 of funnel 1. The thread moves around,

the discharge end 4 and'thus over the series of projections 5 and depressions 10 and over rims 8 and 9 thereby depositing liquid in groove 6. The thread is then collected in the pot in a wavy or undulated manner.

The discharge end 4 is more uniform in its crosssection than the etched type because it can be made from a mold rather than by sand blasting. .Thus it is possible to obtain funnels thatare identical thus insuring a greater thread uniformity from package to package 'as well as within each package.

In addition, these funnels wear longer than the etched funnels because the etched surface wears easily when subjected to thread passage. Also, the thread passing over this end is not cut by .the rims as in the case of etched surfaces.

These funnels should be provided with at least two rims in order that a liquid entraping groove will 'be obtained. It is possible to have more than two rims, however, it has been found that two rims will provide the necessary space for entraping the liquid and will entrap suflicient liquid to provide the antifrictional thread surface. C-rdinarily the funnels will be of such size that there will be only enough surface for two rims, however, if funnels with thicker walls are used, more than two may be used.

The space between the rims or annular grooves should not be too shallow or it will soon wear away. Also, it should not be too deep or the funnel will be weakened and thereby break. It has been found that best results'are obtained if the rims extend in the axial direction between 0.15 and 0.25 mm, thus forming a groove therebetween of a depth of 0:15 to 0.25 mm. 7

These rims should be rounded off in order to prevent any damage to the thread sliding over their surfaces. The space separating these rims should not he too great or the rims will be weakened. It has been found that such should be about 1 mm. in length.

As pointed out in U.S. Patent No. 2,100,595, the projec tions are preferably saw-toothed as shownin the drawing. However, it is also possible tous e this invention with projections which are symmetrically shaped. When using saw-toothed projections the downward sloping edges thereof are preferably in the same direction as the rotation of the spinning pot or centrifuge. Preferably the number of projections should be from two to eight, however, more may be used.

It can be seen from the foregoing thatthis funnel provides an improved antifriction surface of substantial 1. A spinning funnel for use in the manufacture ofrayon according to'the centrifugal process comprising a hollow body portion, a mouth and a discharge end over which the thread is caused to ride, said discharge end having a series of projections and'depressionswhichjare provided with at leasttwo concentric annular rims, said rims extending in the peripheral direction of said funnel and projecting in the axial direction a substantially equal distance.

2. A spinning funnel for use in the manufacture of rayon according to the centrifugal process comprising a hollow body portion, a conical mouth and a discharge end, said discharge end having a series of projections and depressions provided with two concentric annular rims extending in the peripheral direction of. said funnel,

said rims projecting in the axial direction a substantially equal distance for the entrapment of liquid thereby to form an antifriction thread surface. 7

3. A spinning funnel according to claim 2wherein said rims project a distance of 0.15 to 0.25 mm.

4. In a spinning funnel for the manufacture of rayon according to the centrifugal process wherein said funnel is provided with a series of projections and depressions at its discharge end, the improvement comprising at least two concentric annular rims, said rims extending in the peripheral direction of said funnel and projecting in the axial direction a substantially equal distance.

5. In a pot spinning apparatus for the manufacture of rayon, a spinning funnel having a hard thread guiding surface provided with a series of projections and depressions, said projections and depressions having at least two concentric annular rims extending in the peripheral direction of said funnel, said rims projecting inthe axial direction between 0.15 and 0.25 mm. in order to efiect entrapment of liquid thereby providing an antifriction surface for the thread during the operation of the apparatus.

6. A spinning funnel for use in the manufacture of rayon according to the centrifugal process comprising a hollow body portion, a conical mouth and a discharge end, said discharge end having a series of projections and depressions provided with two concentric and spaced annular rims extending in the peripheral direction of said funnel and defining therebetween an annular groove for the entrapment of liquid thereby to form an antifriction thread surface, said rims projecting in the axial direction between 0.15 and 0.25 mm.

No references cited.- 

